undercut

a cut made underneath to remove material

(sports) a stroke that puts reverse spin on the ball

a notch cut in the trunk of tree in order to determine the direction of its fall

the tender meat of the loin muscle on each side of the vertebral column

the material removed by a cut made underneath

cut obliquely into (a tree) below the main cut and on the side toward which the tree will fall

strike (the ball) in golf, tennis, or hockey obliquely downward so as to give a backspin or elevation to the shot

cut away the underpart of

cut away material from the underside of (an object) so as to leave an overhanging portion in relief

sell cheaper than one's competition